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Advice on NA engine


H3nrY

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Hey all

 

I have been having difficulties with the following :

 

6 months ago i let some people in the UK build me an L28 NA high compression engine with the following specs (i´m not a mechanic but I´ll tell you what they told me):

 

-F54 block with P90A head. block hot tank washed, decked&honed, head is gasflowed & ported, skimmed to both faces, fitted S/steel competition valves, 290degree cam, new lash pads and rocker arms. nismo forged pistons

 

I have a 6-2-1 Janspeed full exhaust system and a (custom) 6-carb manifold setup. compression 10:1 on all cylinders.

 

It produces a good 197 rwhp at 6300rpm (dyno tested), so I estimate around 220-230 on the head.

 

It´s not bad at all, but I would like to have more power. I would have to spend a lot more to get more hp out of the NA engine, which I am not willing to do. I have been thinking about turbo.

I would like your opinion on this, before I go charging in.

 

My view is that the pistons would need to be changed to lower the compression? Remove the carb system and add a stable EFI, add a turbo + intercooler & electrics. Does this make sense?

Could someone help me on this and if possible, give me a estimate price tag. My goal would be around 300-340 rwhp.

 

I have searched on this, but did not anything that started from a built NA engine..

 

this is a pic of my current setup:

 

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010061.jpg

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010060.jpg

Thanks

Hendrik

Edited by H3nrY
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Hey all

 

I have been having difficulties with the following :

 

6 months ago i let some people in the UK build me an L28 NA high compression engine with the following specs (i´m not a mechanic but I´ll tell you what they told me):

 

-F54 block with P90A head. block hot tank washed, decked&honed, head is gasflowed & ported, skimmed to both faces, fitted S/steel competition valves, 290degree cam, new lash pads and rocker arms. nismo forged pistons

 

I have a 6-2-1 Janspeed full exhaust system and a (custom) 6-carb manifold setup. compression 10:1 on all cylinders.

 

It produces a good 197 rwhp at 6300rpm (dyno tested), so I estimate around 220-230 on the head.

 

It´s not bad at all, but I would like to have more power. I would have to spend a lot more to get more hp out of the NA engine, which I am not willing to do. I have been thinking about turbo.

I would like your opinion on this, before I go charging in.

 

My view is that the pistons would need to be changed to lower the compression? Remove the carb system and add a stable EFI, add a turbo + intercooler & electrics. Does this make sense?

Could someone help me on this and if possible, give me a estimate price tag. My goal would be around 300-340 rwhp.

 

I have searched on this, but did not anything that started from a built NA engine..

 

this is a pic of my current setup:

 

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010061.jpg

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010060.jpg

Thanks

Hendrik

 

You could get an LD28 Diesel crank out of an 80's maxima and stroke the engine out.

 

KA24E flat top pistons will make it a 3.1l but you have to bore out your block, and you should get some 9mm rods out of a 240z. it will be much cheaper then buying all of the turbo stuff.

 

Its about 1000$ in parts depended where you get them from, i was lucky and got my crank for 70$s

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Turbo will always be cheaper per hp than a stroker. The only high horsepower stroker I saw in person made 274hp or something like that. Building the longblock( machine work, porting, crank and pistons etc.) cost the guy more than $10k. He was running megasquirt with EDIS and I don't even know how much more it cost him to set that up.

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Hey all

 

I have been having difficulties with the following :

 

6 months ago i let some people in the UK build me an L28 NA high compression engine with the following specs (i´m not a mechanic but I´ll tell you what they told me):

 

-F54 block with P90A head. block hot tank washed, decked&honed, head is gasflowed & ported, skimmed to both faces, fitted S/steel competition valves, 290degree cam, new lash pads and rocker arms. nismo forged pistons

 

I have a 6-2-1 Janspeed full exhaust system and a (custom) 6-carb manifold setup. compression 10:1 on all cylinders.

 

It produces a good 197 rwhp at 6300rpm (dyno tested), so I estimate around 220-230 on the head.

 

It´s not bad at all, but I would like to have more power. I would have to spend a lot more to get more hp out of the NA engine, which I am not willing to do. I have been thinking about turbo.

I would like your opinion on this, before I go charging in.

 

My view is that the pistons would need to be changed to lower the compression? Remove the carb system and add a stable EFI, add a turbo + intercooler & electrics. Does this make sense?

Could someone help me on this and if possible, give me a estimate price tag. My goal would be around 300-340 rwhp.

 

I have searched on this, but did not anything that started from a built NA engine..

 

this is a pic of my current setup:

 

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010061.jpg

http://i813.photobucket.com/albums/zz51/H3nrY_/Datsun%20260Z/P1010060.jpg

Thanks

Hendrik

 

I really like your setup, and those are decent numbers at the wheels.

 

I am assuming that the carbs you are using are motorcycle, correct? Who made the intake manifold, and do you have a thread here on hybrid showing how?

 

Are the pistons flat top? Did they cut the head to get the higher CR?

 

Thanks,

 

Pete

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I dunno, just economics really and it seems a shame to tear down a nicely built NA engine. You can sell that NA engine for, maybe $5,000 complete, and use that money for a new build. If you're modifying the existing engine you're throwing away the intake, exhaust, carbs, cam, and pistons. Maybe you can sell those parts separately but they are worth more as part of a complete engine.

 

I've never been too impressed with a low boost high compression engine. All that extra plumbing and complexity for 5 psi? Might as well just keep the NA engine and spend that additional money on lightening the car and making it handle better. Or start over and build a turbo engine.

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I'll also add that setup could be of interest in Europe since we do have some classic rally races. People are bored with 911's and start to think about alternatives. Z's are nice choices, this engine could meet Group 4 specifications and make wealthy racers happy as long as you've got all the data that goes with such motors.

 

On the other hand, it is not so easy to find a L28 in Europe to make a turbo engine so it could become a challenge to build a cheap setup.

 

The target you're trying to reach with turbo setup seems also out of range with NA (or close to be). So if it is really what you want, I would advice selling this combo.

 

So keep it and enjoy or go turbo! :)

 

I don't know who build this engine for you but there's definitely some support for Datsun in UK or France if you like to build such setup ;)

Edited by Lazeum
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On the other hand, it is not so easy to find a L28 in Europe to make a turbo engine so it could become a challenge to build a cheap setup.

 

it's the same in Australia, most of my turbo bolt on parts came from the US.

 

I assume Nissan sold Nissan Patrols in Europe, some of these had the L28 in them,

 

160 Series (MQ / MK), 1980–1987 Australia,

260 Series, 1986–1994 , The 260 series was a Spanish-built version of the 160 (easily spotted by the rectangular headlamps) sold in Europe and was available in SWB / LWB and with L28

 

http://en.wikipedia.org/wiki/Nissan_Patrol

 

Nigel

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You're right, we can find L28 but cars that go with L28 are rare. So no way you'll find a motor at the junkyard. So the only way is to get a car with the engine it. Then it is impossible to part the car out.

It happened once or twice somebody would have got 2 cars to make one, then an engine would be available...

 

In Europe, s30 & s130 are quite expensive. A good 240z is worth 15,000 / 20,000 € and a 280zx NA 2+2 around 8,000 € whereas a 280zx rusty shell would be aorund 2,000€.

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When I was looking 3 months ago Stroker cranks were $500++ IF you could find one. The whole Stroker setup added a major bump in price for pistons, crank, head gasket, etc and truly only a mild bump in HP which you would quickly grow into and begin to resent.

 

Possible to take your existing setup and put in a put in a 2mm Head Gasket to get the C/R low enough for turbo?

 

I didn't trust myself with a turbo motor so I stayed NA which is pretty hard to blow up.

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I did find a L28 turbo (unmodified) from a 280ZX turbo, but hes asking 900 euros without ancillaries because, as already stated, these engines are pretty rare.

 

I did not realise though it would be such a large modification to the car when just changing to a turbo engine (exhaust etc..)

 

I´ll see if I can drop something of that price for the turbo engine. Ill check how much i can get for my current engine (has about 1200 km).

 

What do you reckon the price would be for all the changes I´ll have to make to get some decent outputs from the stock turbo engine?

 

thanks all for you input !

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As john said, you're better of selling and starting over from a stock turbo motor.

 

That said though, your compression is probably just about perfect for running E85 if it's available over there.

 

Regarding your last question though, you can get 350whp out of a L28ET (stock 280ZX turbo motor) without taking off the valve cover. Let me rattle of what I can think of off the top of my head.

 

Needed:

L28ET Longblock

T3/T4 hybrid turbo (or holset or something similarly sized)

500cc+ injectors

Manual boost controller

Intercooler + plumbing

Decent BOV (recirculating type can help with maintaining turbo spool)

RRFPR (if using stock EFI)

Custom turbo-back exhaust (MSA makes a downpipe for S30 application if you want something over the counter)

High pressure fuel filter

High pressure fuel pump

 

 

Recommended:

Megasquirt or better aftermarket EFI system

Wideband O2 with datalogging capability

Fuel Rail

Better fuel lines

 

 

In the US I could purchase all that for under $3k easily, but I'd also be doing a lot of work myself. Since you stated yourself that you're not extremely mechanical you're probably going to have someone else do it, so you're entirely up to the mercy of them and their rate of hire.

 

I personally like the L28ET because if you're on a budget you can get away with changing very little to get to 300hp and it helps keep the budget low. You CAN spend a lot of money doing it "right" but I've seen very few actually put the time and energy in doing it "right". There's many more of us with hobbled together setups using lots of stock parts and making it work.

 

All that said, you can just go get a RB25DET which is much more available in Europe than here, and be done with it. 350whp is a walk in the park and you can even leave the stock turbo in there. Instead of spending $3k on modifying an engine you'll be spending $3k to buy the motor and put it in, and then spending a few bucks on getting someone to tune it.

 

But swaps aren't for everyone. So it's just a thought. :wink:

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I was debating on if I should post because all that has been said was what I was thinking. But I just wanted to say WOW that setup looks amazing! Love the work that has been put in there.

 

For not being mechanical ( sounds more like intimidated to me) a turbo build with tearing the old motor down seems like wasted money and time. Not sure how you feel on swaps but as stated the RB, BMW, and Merc straight six's are vital options as well. Most are close to drop in and go. You might get over your mechanical fears while tinkering too!

 

Any who, not sure if the rest of the body looks like the engine bay but you have a great looking under hood area.......

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Any reason you havent looked into getting some more head work done and getting a bigger cam? Even if you go turbo you are looking at spending in the thousands more. Maybe a 300 duration 500 liftish cam with the appropriate headwork will give you enough hp to keep you happy? Everything about hotting up Lseries N/A always seems to come back to one thing - how much you can make the head flow. With the forged pistons you will be able to rev it harder too and that's how N/As make power.

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Are those old Triumph Tiger Carbs (before they went to EFI???) Unique solution indeed.

 

I'm with John Coffey up to the 5psi low boost turbo part... It's amazing the boost response you get in a well ported and cammed engine. But I agree you should just sell it as-is and start another dedicated build.

 

Why go to the UK, doesn't Miroux do that work on the side? They have a nice 240 they run at Spa 6 Hours every year. Though I'm apparently banned from their pits (as well as Frank 280ZX) after questioning the F54 block "L24" they SWEAR they are using to run times equivalent to GT350 Shelby's around the course there...

 

Speaking of which, if you go to Spa Sept 23,24,25 look for me, I should be there! Hanging around the S30's that show up for sure!

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Not trying to be too sarcastic, but this IS Hybridz, why not put in a more modern alternative, such as an RB25 or 1JZ? It might wind up costing about the same, in your case, easier to source, with better technology & more power. I don't know about the legality in your area though...Plenty of 1JZ's have made more than 300 rwhp with only a downpipe, intake & free flowing exhaust as mods...and the response is incredible!

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